Module: E2B::DockerfileParser

Defined in:
lib/e2b/dockerfile_parser.rb

Class Method Summary collapse

Class Method Details

.handle_cmd(value, template_builder) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 165

def handle_cmd(value, template_builder)
  return if value.strip.empty?

  command = value.strip
  begin
    parsed = JSON.parse(command)
    command = parsed.join(" ") if parsed.is_a?(Array)
  rescue JSON::ParserError
    nil
  end

  template_builder.set_start_cmd(command, E2B.wait_for_timeout(20_000))
end

.handle_copy(value, template_builder) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 105

def handle_copy(value, template_builder)
  return if value.strip.empty?

  parts = Shellwords.split(value)
  user = nil
  non_flag_parts = []

  parts.each do |part|
    if part.start_with?("--chown=")
      user = part.delete_prefix("--chown=")
    elsif !part.start_with?("--")
      non_flag_parts << part
    end
  end

  return unless non_flag_parts.length >= 2

  src = non_flag_parts.first
  dest = non_flag_parts.last
  template_builder.copy(src, dest, user: user)
end

.handle_env(value, keyword, template_builder) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 139

def handle_env(value, keyword, template_builder)
  return if value.strip.empty?

  parts = Shellwords.split(value)
  envs = {}

  if parts.length == 1
    parse_single_env_part(parts.first, keyword, envs)
  elsif parts.length == 2 && !(parts[0].include?("=") && parts[1].include?("="))
    envs[parts[0]] = parts[1]
  else
    parts.each { |part| parse_single_env_part(part, keyword, envs) }
  end

  template_builder.set_envs(envs) unless envs.empty?
end

.handle_run(value, template_builder) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 99

def handle_run(value, template_builder)
  return if value.strip.empty?

  template_builder.run_cmd(value.strip.gsub(/\s+/, " "))
end

.handle_user(value, template_builder) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 133

def handle_user(value, template_builder)
  return if value.strip.empty?

  template_builder.set_user(value.strip)
end

.handle_workdir(value, template_builder) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 127

def handle_workdir(value, template_builder)
  return if value.strip.empty?

  template_builder.set_workdir(value.strip)
end

.normalize_base_image(value) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 95

def normalize_base_image(value)
  value.sub(/\s+as\s+.+\z/i, "").strip
end

.parse(dockerfile_content_or_path, template_builder) ⇒ Object

Raises:



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# File 'lib/e2b/dockerfile_parser.rb', line 10

def parse(dockerfile_content_or_path, template_builder)
  instructions = parse_instructions(read_dockerfile(dockerfile_content_or_path))
  from_instructions = instructions.select { |instruction| instruction[:keyword] == "FROM" }

  raise TemplateError, "Multi-stage Dockerfiles are not supported" if from_instructions.length > 1
  raise TemplateError, "Dockerfile must contain a FROM instruction" if from_instructions.empty?

  base_image = normalize_base_image(from_instructions.first[:value])
  user_changed = false
  workdir_changed = false

  template_builder.set_user("root")
  template_builder.set_workdir("/")

  instructions.each do |instruction|
    keyword = instruction[:keyword]
    value = instruction[:value]

    case keyword
    when "FROM"
      next
    when "RUN"
      handle_run(value, template_builder)
    when "COPY", "ADD"
      handle_copy(value, template_builder)
    when "WORKDIR"
      handle_workdir(value, template_builder)
      workdir_changed = true
    when "USER"
      handle_user(value, template_builder)
      user_changed = true
    when "ENV", "ARG"
      handle_env(value, keyword, template_builder)
    when "CMD", "ENTRYPOINT"
      handle_cmd(value, template_builder)
    end
  end

  template_builder.set_user("user") unless user_changed
  template_builder.set_workdir("/home/user") unless workdir_changed

  base_image
end

.parse_instructions(content) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 64

def parse_instructions(content)
  instructions = []
  current = +""

  content.each_line do |raw_line|
    line = raw_line.chomp
    next if line.strip.empty? || line.lstrip.start_with?("#")

    if line.rstrip.end_with?("\\")
      current << line.rstrip.sub(/\\\s*\z/, "")
      current << " "
      next
    end

    current << line
    instruction = current.strip
    current = +""
    next if instruction.empty?

    keyword, value = instruction.split(/\s+/, 2)
    instructions << { keyword: keyword.upcase, value: value.to_s.strip }
  end

  unless current.strip.empty?
    keyword, value = current.strip.split(/\s+/, 2)
    instructions << { keyword: keyword.upcase, value: value.to_s.strip }
  end

  instructions
end

.parse_single_env_part(part, keyword, envs) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 156

def parse_single_env_part(part, keyword, envs)
  equal_index = part.index("=")
  if equal_index && equal_index.positive?
    envs[part[0...equal_index]] = part[(equal_index + 1)..]
  elsif keyword == "ARG" && !part.strip.empty?
    envs[part.strip] = ""
  end
end

.read_dockerfile(dockerfile_content_or_path) ⇒ Object 



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# File 'lib/e2b/dockerfile_parser.rb', line 54

def read_dockerfile(dockerfile_content_or_path)
  if File.file?(dockerfile_content_or_path)
    File.read(dockerfile_content_or_path)
  else
    dockerfile_content_or_path
  end
rescue StandardError
  dockerfile_content_or_path
end